This invention relates to an information recording-reproducing apparatus which records and/or reproduces information on a recording medium, such as a CD (compact disc) and a DVD (digital versatile disc), and more particularly to an information recording-reproducing apparatus of this kind, which has a slot-in type carrier mechanism provided therefor, for installing and ejecting the recording medium.
There are known information recording-reproducing apparatuses having a slot-in type carrier mechanism provided therefor, among which is an information reproducing apparatus mounted in vehicles, i.e. an in-vehicle information reproducing apparatus. The conventional in-vehicle information reproducing apparatus includes carrier mechanism composed of carrier rollers which carry a recording medium into the interior of the apparatus (loading) and eject the recording medium from the apparatus (unloading), and photo sensors which detect the position of the recording medium. The carrier rollers are controlled based on detection signals output from the photo sensors, to thereby carry out the above-mentioned loading and unloading of the recording medium.
In these years, however, various types of recording media have been developed which are the same in information recording and reproducing method but different in standard. For instance, with respect to CD""s (compact discs), in addition to two conventionally known discs, i.e. a 8-cm diameter disc and a 12-cm diameter disc, a Maxi single disc has been standardized recently. To cope with the variety of the types, it is a significant challenge for the information reproducing apparatus to enhance its general applicability, i.e. to be applicable to any discs irrespective of their types.
FIGS. 14 to 16 show the formats of a 8-cm diameter disc, a 12-cm diameter disc, and a Maxi single disc, respectively. The 8-cm diameter disc (see FIG. 14) includes a center hall having a bore diameter of 15 mm, a clamping area having a diameter of 33 mm, and a program area, on which information is recorded, at an outer periphery thereof outside a circle having a diameter of 50 mm. On the other hand, the 12-cm diameter disc (see FIG. 15) includes a center hole and a clamping area which are the same in diameter as the 8-cm diameter disc, and a program area at an outer periphery thereof outside a circle having a diameter of 50 mm.
The Maxi single disc (see FIG. 16) which has been standardized recently has a diameter of 120 mm, and includes a center hole and a clamping area which are the same in diameter as the 8-cm diameter disc, and a program area at an outer periphery thereof defined by an inner circle having a diameter of 50 mm and an outer circle having a possible maximum diameter of 82 mm. In other words, the Maxi single disc is formatted to have both the standards of the 8-cm diameter disc and the 12-cm diameter disc. However, its program area is set almost the same area as the 8-cm diameter disc, and therefore an outer peripheral area AR outside the 82-mm diameter circle is not the program area. The outer peripheral area AR may be formed of a transparent material or an opaque material, on which pictures, letters, or graphics may be drawn.
As mentioned hereinabove, since various types of the discs exist which are the same in information recording and reproducing method but different in format, it is a significant challenge to impart general applicability to an information recording-reproducing apparatus. Especially, to positively install and eject the disc, the carrier mechanism is required to have improved accuracy in sensing the difference between the types of the discs.
In addition to the above mentioned discs in various types, there is conventionally proposed a toroidal adapter (see FIG. 17) with which the 8-cm diameter disc is treated as the 12-cm diameter disc in appearance.
The adapter is formed to have a 12-cm diameter and therein a circular hole BR having a diameter of 80 mm, in which the 8-cm diameter disc is mounted. By mounting the 8-cm diameter disc in the circular hole BR, the disc as a whole can be treated similarly to the 12-cm diameter disc.
However, the adapter like this can cause the following disadvantage: For example, the user can insert the adapter into the information recording-reproducing apparatus without mounting the 8-cm diameter disc. In such a case, the adapter must be quickly ejected as a foreign matter, to thereby prevent an unexpected accident beforehand. The real discs should be discriminated from not only the adapter shown in FIG. 17 but also any types of foreign matters, and therefore when the foreign matter is inserted, it should be positively ejected, to thereby prevent an unexpected accident.
It is therefore an object of the invention to provide an information recording-reproducing apparatus which has general applicability to discs manufactured according to different standards as well as be capable of preventing an unexpected accident caused by insertion of a foreign matter.
To attain the object, the invention provides an information recording-reproducing apparatus intended for carrying and installing a large diameter disc-type recording medium and a small diameter disc-type recording medium, including a carriage path, and carrier means for carrying the recording medium along the carriage path. The information recording-reproducing apparatus comprises optical detecting means arranged in the carriage path at a location close to the carrier means, for optically detecting the recording medium when the recording medium passes through the carriage path, mechanical detecting means arranged in the carriage path at a location close to the carrier means and outside the optical detecting means with respect to a center of the carriage path, for mechanically detecting the recording medium when the recording medium passes through the carriage path, and determining means for determining whether an inserted object is the large diameter disc-type recording medium, a small diameter disc-type recording medium, or an object not to be installed, based on detection signals output from the optical detecting means and the mechanical detecting means.
Preferably, the carriage path has a width almost equal to a diameter of the large diameter recording medium, the mechanical detecting means being arranged at one peripheral end of the carriage path.
More preferably, the optical detecting means are comprised of a first optical detector and a second optical detector, the first optical detector and the second optical detector being arranged at an interval smaller than a diameter of the small diameter recording medium, the first optical detector and the mechanical detecting means being arranged at an interval larger than the diameter of the small diameter recording medium, the second optical detector and the mechanical detecting means being arranged at an interval smaller than the diameter of the small diameter recording medium.
According to the arrangement, the large diameter disc-type recording medium is detected based on the detection signals output from the first and second optical detectors and the mechanical detecting means, while the small diameter disc-type recording medium is detected based on the detection signals output from the first and second optical detectors.
Further preferably, the information recording-reproducing apparatus includes control means for controlling the carrier means, wherein the control means output a control signal for instructing an ejecting operation to the carrier means when the determining means determine that the inserted object is the object not to be installed, the carrier means performing the ejecting operation in response to the control signal.
According to the arrangement, when a foreign matter other than the real recording medium or the like is inserted into the apparatus, the foreign matter is ejected out of the apparatus, and the carrier means are stopped. As a result, the apparatus can be prevented from being damaged.